2021
Short-term overnutrition induces white adipose tissue insulin resistance through sn-1,2-diacylglycerol – PKCε – insulin receptorT1160 phosphorylation
Lyu K, Zhang D, Song J, Li X, Perry RJ, Samuel VT, Shulman GI. Short-term overnutrition induces white adipose tissue insulin resistance through sn-1,2-diacylglycerol – PKCε – insulin receptorT1160 phosphorylation. JCI Insight 2021, 6: e139946. PMID: 33411692, PMCID: PMC7934919, DOI: 10.1172/jci.insight.139946.Peer-Reviewed Original ResearchConceptsInsulin resistanceInsulin actionAdipose tissue insulin resistanceTissue insulin resistanceWT control miceHyperinsulinemic-euglycemic clampShort-term HFDTissue insulin actionAdipose tissue insulin actionDiet-fed ratsPotential therapeutic targetHFD feedingControl miceInsulin sensitivityTherapeutic targetLipolysis suppressionImpairs insulinHFDPKCε activationGlucose uptakeΕ activationMiceDiacylglycerol accumulationRecent evidenceProtein kinase C
2019
Adipose glucocorticoid action influences whole‐body metabolism via modulation of hepatic insulin action
Abulizi A, Camporez JP, Jurczak MJ, Høyer KF, Zhang D, Cline GW, Samuel VT, Shulman GI, Vatner DF. Adipose glucocorticoid action influences whole‐body metabolism via modulation of hepatic insulin action. The FASEB Journal 2019, 33: 8174-8185. PMID: 30922125, PMCID: PMC6593882, DOI: 10.1096/fj.201802706r.Peer-Reviewed Original ResearchConceptsWhole-body metabolismHepatic insulin actionHepatic insulin resistanceGlucocorticoid actionHepatic steatosisHepatic glycogen synthesisInsulin resistanceAdipose lipolysisFood intakeInsulin actionAdipose triglyceride lipase expressionGlucose-dependent organsReceptor knockout miceOral glucose challengeHepatic lipid accumulationHigh-fat dietHyperinsulinemic-euglycemic conditionsGlycogen synthesisProtein kinase B phosphorylationInsulin responseGlucose challengeHepatic insulin responseHepatic insulinMetabolic cagesSteatosis
2016
Insulin receptor Thr1160 phosphorylation mediates lipid-induced hepatic insulin resistance
Petersen MC, Madiraju AK, Gassaway BM, Marcel M, Nasiri AR, Butrico G, Marcucci MJ, Zhang D, Abulizi A, Zhang XM, Philbrick W, Hubbard SR, Jurczak MJ, Samuel VT, Rinehart J, Shulman GI. Insulin receptor Thr1160 phosphorylation mediates lipid-induced hepatic insulin resistance. Journal Of Clinical Investigation 2016, 126: 4361-4371. PMID: 27760050, PMCID: PMC5096902, DOI: 10.1172/jci86013.Peer-Reviewed Original ResearchConceptsInsulin receptorKinase activityHigh-fat diet-induced hepatic insulin resistanceKinase activation loopNonalcoholic fatty liver diseaseLipid-induced hepatic insulin resistanceProtein kinase CHepatic insulin resistanceDiet-induced hepatic insulin resistanceDiacylglycerol-mediated activationActivation loopPKCε inhibitionAlanine mutationsInsulin resistanceMolecular mechanismsKinase CCritical pathophysiological rolePathogenesis of T2DMechanistic linkMutantsGlycogen synthesisConsequent inhibitionPhosphorylationActive configurationPKCε
2013
Thyroid hormone receptor-β agonists prevent hepatic steatosis in fat-fed rats but impair insulin sensitivity via discrete pathways
Vatner DF, Weismann D, Beddow SA, Kumashiro N, Erion DM, Liao XH, Grover GJ, Webb P, Phillips KJ, Weiss RE, Bogan JS, Baxter J, Shulman GI, Samuel VT. Thyroid hormone receptor-β agonists prevent hepatic steatosis in fat-fed rats but impair insulin sensitivity via discrete pathways. AJP Endocrinology And Metabolism 2013, 305: e89-e100. PMID: 23651850, PMCID: PMC3725564, DOI: 10.1152/ajpendo.00573.2012.Peer-Reviewed Original ResearchMeSH KeywordsAcetatesAnilidesAnimalsDietary FatsFatty LiverGene ExpressionGluconeogenesisGlucose Transporter Type 4HyperglycemiaHyperinsulinismInsulin ResistanceMaleMuscle, SkeletalNon-alcoholic Fatty Liver DiseasePhenolsRatsRats, Sprague-DawleySignal TransductionThyroid Hormone Receptors betaTriglyceridesConceptsEndogenous glucose productionHepatic insulin sensitivityInsulin sensitivityHepatic steatosisFat-fed ratsInsulin-stimulated peripheral glucose disposalTRβ agonistsInsulin-stimulated skeletal muscle glucose uptakePotent lipid-lowering drugsNonalcoholic fatty liver diseaseWhite adipose tissue lipolysisMale Sprague-Dawley ratsSkeletal muscle glucose uptakeGC-1 treatmentPeripheral glucose disposalFatty liver diseaseImpairs insulin sensitivityLipid-lowering drugsHepatic triglyceride contentAdipose tissue lipolysisMuscle glucose uptakeSprague-Dawley ratsHepatic insulin resistanceSkeletal muscle insulinPotential adverse effects
2010
Deletion of the α-Arrestin Protein Txnip in Mice Promotes Adiposity and Adipogenesis While Preserving Insulin Sensitivity
Chutkow WA, Birkenfeld AL, Brown JD, Lee HY, Frederick DW, Yoshioka J, Patwari P, Kursawe R, Cushman SW, Plutzky J, Shulman GI, Samuel VT, Lee RT. Deletion of the α-Arrestin Protein Txnip in Mice Promotes Adiposity and Adipogenesis While Preserving Insulin Sensitivity. Diabetes 2010, 59: 1424-1434. PMID: 20299477, PMCID: PMC2874703, DOI: 10.2337/db09-1212.Peer-Reviewed Original ResearchConceptsTxnip knockout miceInsulin resistanceInsulin sensitivityKnockout miceInsulin responsivenessTXNIP expressionSkeletal muscleWild-type littermate control miceStandard chow dietType 2 diabetes pathogenesisHigh-fat dietHigh-fat feedingLittermate control miceGene-deleted miceInhibits glucose uptakeControl miceChow dietAdipose massMore insulinCaloric excessFat massDiabetes pathogenesisMouse embryonic fibroblastsRegulator of adipogenesisPPARgamma expression
2009
Fasting hyperglycemia is not associated with increased expression of PEPCK or G6Pc in patients with Type 2 Diabetes
Samuel VT, Beddow SA, Iwasaki T, Zhang XM, Chu X, Still CD, Gerhard GS, Shulman GI. Fasting hyperglycemia is not associated with increased expression of PEPCK or G6Pc in patients with Type 2 Diabetes. Proceedings Of The National Academy Of Sciences Of The United States Of America 2009, 106: 12121-12126. PMID: 19587243, PMCID: PMC2707270, DOI: 10.1073/pnas.0812547106.Peer-Reviewed Original ResearchMeSH KeywordsAdultAnimalsDiabetes Mellitus, Type 2Dietary FatsFastingFeeding BehaviorFemaleGene Expression Regulation, EnzymologicGluconeogenesisGlucose-6-PhosphataseHumansHyperglycemiaHyperinsulinismInsulin Infusion SystemsLiverMaleMiddle AgedPhosphoenolpyruvate Carboxykinase (ATP)RatsRats, Sprague-DawleyStreptozocinConceptsHigh-fat feedingEndogenous glucose productionHFF ratsExpression of PEPCKHepatic expressionType 2 diabetes mellitusBeta-cell compensationBeta-cell responseFirst rat modelPortal vein infusionLiver biopsy samplesHigher plasma glucosePhosphoenolpyruvate carboxykinaseBariatric surgeryT2DM patientsDiabetes mellitusInsulin resistancePlasma insulinPlasma glucosePortal infusionRat modelRodent modelsVein infusionHyperglycemiaKey gluconeogenic enzymes